1. Field of the Invention
The present invention relates to touch-panel input devices having functions for providing vibrations and methods for providing vibrations in response to input operations, and more particularly to an input device having a force-feedback (FFB) function for providing vibrations to a user when the user operates a touch panel.
2. Description of the Related Art
A touch-panel input device A touch-panel input device including a panel-shaped input operation unit on the surface of a liquid crystal display is known. In Japanese Unexamined Patent Application Publication No. 8-221173, a touch-panel input device is disclosed. This touch-panel input device has a function for providing vibrations to an operator through a vibrator when the operator touches a switch displayed on a screen of a touch panel to inform the operator of, for example, a position and the type of the switch, i.e., an FFB function. Hereinafter, this type of touch-panel input device is referred to as an FFB touch panel.
Moreover, a device for generating sounds by vibrating a transparent panel on the front surface of a liquid crystal screen as a speaker is known. Hereinafter, this type of device is referred to as a panel-type speaker. Moreover, a device serving as a microphone for inputting speech by transmitting vibrations generated on a transparent panel on the front surface of a liquid crystal screen when a user speaks to the liquid crystal screen is known. Hereinafter, this type of device is referred to as a panel-type microphone.
When a device includes a touch panel serving as both the FFB touch panel and the panel-type speaker described above, the device vibrates the touch panel to provide force feedback to a user and to generate voice output. In this case, when this touch panel is used as a speaker by vibrating the touch panel and the user operates a switch displayed on the touch panel at the same time, vibrations of the speaker cannot be distinguished from those of force feedback. Thus, vibrations corresponding to the operation of the switch cannot be smoothly transmitted to the user.
When a device includes a touch panel serving as both the FFB touch panel and the panel-type microphone described above, the device vibrates the touch panel to provide force feedback to a user and allows voice input by transmitting vibrations generated on the touch panel in response to the user's voice. In this case, when the touch panel is used as a microphone and the user operates a switch displayed on the touch panel at the same time, the touch panel may vibrate in response to the operation of the switch and the vibrations may be erroneously transmitted as voice input.
Accordingly, when the device includes a touch panel serving as the FFB touch panel and the panel-type speaker, an input operation mode and a speaker mode are set up as operation modes. In this arrangement, when the user performs an input operation using the touch panel as the FFB touch panel, the user must temporarily change the operation mode from the speaker mode to the input operation mode by, for example, operating a hardware key provided at a location other than the touch panel, the key serving as a mode-change switch.
Similarly, when the device includes a touch panel serving as the FFB touch panel and the panel-type microphone, the input operation mode and a microphone mode are set up as operation modes. In this arrangement, when the user performs the input operation using the touch panel as the FFB touch panel, the user must temporarily change the operation mode from the microphone mode to the input operation mode by, for example, operating a hardware key provided at a location other than the touch panel, the key serving as a mode-change switch.
In both cases, the user must operate the hardware key provided at the location other than the touch panel when the user performs the input operation using the touch panel as the FFB touch panel. Thus, the operation is disadvantageously complicated.